So I played a Tavern Brawl game earlier where I was using the Dragon Warrior recipe and my opponent the Buffadin one. They were doing Immortal Prelate shenanigans, and weirdly I noticed that Equality had stuck to it as an enchantment (I figured that only single-target spells would apply, but clearly this is a misconception of mine as the card doesn't specifically state this). Later on in the game I got Nightmare off of Ysera, and had the (what I thought was a) clever idea to cast it on my opponent's Prelate. My thinking was that now whenever they summoned that same Prelate it would come out with the +5/+5 but not be able to attack that turn, and then at the start of my opponent's next turn it would immediately die. I quite liked the idea of my opponent's buffed Prelate being doomed to an eternity of death by Nightmare.
This didn't work.
On subsequent summons it didn't have the +5/+5, and in fact Nightmare wasn't even listed amongst the card's "enchantments". Now Immortal Prelate does not specifically state that the enchantments have to be yours, so why Nightmare wasn't kept is a mystery to me. It just seems very odd that Equality counts as an enchantment, yet an opposing Nightmare doesn't.
[Disclaimer: This isn't a salt thread. Yes this inconsistency may have contributed somewhat to me losing that game, but that isn't why I'm bringing it up. I am legitimately puzzled as to why this is the case.]
Seems like a bug, I suspect due to Nightmare being a generated card and a 'start of turn' effect. Also suggests spaghetti code if effects have to be coded individually, easy to miss one when your solution 'looks like a computer' and not a card game.